Mechanical stoker.



J. P. DAVIS. MECHANICAL STOKiR. APPLICATION FILED my 6. m5.

Patented June 13, 1916.

3 SHEETS-SHEET I.

J P. DAVIS.

MECHANICALSTOKER. APPLICATION man MAY 6i 1915.

1 1 86,97 1 Patented June 13, 1916.

3 SHEETS SHEET 3.

Wflmamo 6 f fwum.

JENKIN P. DAVIS, OF CINCINNATI, OHIO.

MECHANICAL STOKER.

Specification of Letters'Patent. Patented June 13, 1916.

Application filed May 6, 1915. Serial No. 26,296.

To all whom it may concern:

Be it known that I, JENKIN P. DAVIS, a

citizen of the United States of America, and resident of Cincinnati, county of Hamilton, State of Ohio, have invented certain new and useful Improvements in Mechanical Stokers, of which the following is a specification.

This invention relates to improvements in mechanical stokers and particularly to mechanical stokers of the class employing inclined agitating grates in which the fuel is delivered to the uppermost-portions of the grates and is gradually worked to the lowermost portions thereof during the process of combustion.

An object of my invention is to produce a mechanical stoker adapted to create a high rate of combustion with a minimum amount of fuel.

- A further object is to produce a mechanical stoker which is adapted to create more.

thorough combustion of the fuel and to consequently eliminate a great proportion of the smoke produced from ordinary stokers.

A further object is to produce a mechanical stoker in which a series of continuously moving fuel feeders, coking plates and grate bars are provided and mounted in such a manner that the fuel isproperly distrib- I uted over the grate bars to produce greater efliciency with a materially simplified stoker construction.

These and other objects are attained in the stoker described in the following specification and illustrated in the accompanying drawings in which;

Figure 1 is aside elevation of a stoker embodying my invention, with the frame members .on one side removed and certain parts shown in section to more fully illustrate the interior construction thereof. Fig. 2 is a front elevation of the stoker. Fig. 3 is a plan view of the stoker. Fig. 4 is a fragmental sectional view of a detail of the stoker. Fig. 5 is a plan view' of the engine for operating the stok'erl The stoker embodying my invention consists of a frame 6 built up of two side frame members 7 and 8 connected by transversely extending channel and angle iron members. 9 and 10 adjacent to the bottom of the frame, and by means of plates 11 and 12 forming a hopper 13, at the top of the frame. Mounted on the front of the frame is a mechanism 14 from which the interior mechanism of the stoker receives its mo-' tion, and back of the front of the stoker are located a series of coking plates 15 which extend transversely of the frame and which are adapted, to discharge fuel onto a series of grate bars 16 which extendlongitudinally and which are mounted at one end on the frame 6 and at their opposite end on a secondary frame 17 located at the rear of the furnace and at a lower level than the frame 6. This frame 17 consists of side members 18 and 19 connected with one another 'by means of the angle irons 20 and 21 extending across the back and by means of T-irons 22 and 23 extending across the top adjacent to the front of the side members. Upon this frame is located the retarding grate 24,

and to the rear of the retarding grate is located the dumping grate 25.

In addition to the coking plates 15 and the grate bars 16, the frame 6 has mounted upon it a movable member 26 which is located at the bottom of the hopper 13 and which acts as a fuel feeder adapted to push the fuel from the bottom of the hopper and to discharge the fuel onto a concave plate 27 located above the poking plates 15 and adapted to act as a distributing plate for the fuel delivered from the hopper. In front of this plate is located it movable member 28 which is similar to the member 26,bu t which operates as a fuel piisher for the purpose of pushing the fuel from the plate27 onto the coking plates 15. This fuel pusher operates alternately with the fuel feeder 26 and is connected with the operating mecha nism 1 1. In addition to theconnectio'n of the fuel feeder 26 and the fuel pusher 28,

the coking plates 15 which are mounted in anism 14 by means of links 29 and 30. The grate bars 16 located to the rear of the 00k;

ing plates 15 are also connected with the mechanism 14 by means of a link 31, in the same manner that the links 29 and 30 are connected therewith. The retarding grate 24 is a stationary grate and is intended to merely retard the delivery of unconsumed fuel to the dumping grate 25 for the purpose of permitting complete combustion of the. fuel before it is pushed. on the dumping grates, from which the fuel is discharged into the ash pit of the furnace.

'Inthe operation of my improved stoker I provide for alternate movement of the coking plates 15 end the grate bars 16in addition to the alternate movement of the fuel feeder 26 and the fuel pusher 28. This alternate movement of the movable members is secured by suitable connections with the operating mechanism 14 which I will now describe.

Extending transversely of the Stoker is a shaft 32 and a shaft 33, both of which are adapted to receive an oscillating motion from a short shaftwhichis connected with the engine illustrated in Fig. in the following manner: The engine is preferably one of the re iproceting' type in which the piston rod is adapted to move back werdly and forwardly, and is connected with an arm efteuding downwardly from the shaft. 34 the purpose of roclo ing the erm'and the sneft us the piston rod moves in and c1 lfoniwcteil with the shaft is an arm 34; nit-l2. extends toward the front and whicl connected with links 37 l and 38 secured to the 1e. are arms 39 and 40 mounted on a respe p shafts 32 and By this in .uns t e some mot-ion co1nniuniceted by the engine to the shaft 34 is communicated to the shafts 3'2 and Mounted on the shaft 8:?- are a series of dowmverdiy extending Arms or cranks 41 which are connected with the fuel feeder 26 for the purpose of operating the several portions thereon.

. meens theft l'pusher 28 and the grate bars 16 are feeder being prefer ably constructed in several parts illustratcd in F for the purpose of per-- mittingr adjustn t of the several, port-ions to discharge the cor-i eu'iount of fuel onto the plate 27, to effect proper distribution thereof throughout travel toward the dumping grate. This adjustable connection between the portions of the. feeder 26 and the crank arms 4!. will be hereinafter more fully described.

Mounted on the shaft 38 at points adjucent to the opposite sides of the frame are double arms 42 to which the links 29, 30 and 31, connected with the coking plates and the grate bars, are connected. In addition to the connection of the links 2-9. 30 and 31 with the double arm cranks 42-, the fuel pusherQS is also connected therewith at the upper end. of the branch 42* of the arm. At the lower end of the arm, the link 31 which operates the alternately moving bars 16, is .on riected, and adjacent to the shaft inks 29 and 30 are connected. By f tl sconncction it will be seen that given n somewhat greater movement than the coking plates 15. These coking plates are connected in alternate pairs with the links 29 and 30 so that the plates 43 and 44 are adapted to be ope 'ated by the link 3?. The links being located on opposite sides of the shaft 33 will be given movement'in opposite directiims to one another, so that- ,to their substantially level positions, while the plates 45 and 46 are charge fuel therefrom, position receiving fuel being tipped to dis-. the plate 43 in this 7 from the distributing plate 27 and the plate 44 receiving the fuel previously contained on the plate 45.

The grate bars 16 like the coking plates 15 are provided with two series of oppositely moving burs, one series 47 being alternately disposed with the other series 48 so that when the series 47 is moving in one direction the series 48 will be moving in the opposite direction. To secure this motion the grate bars are provided with bearing lugs 49 and 50 on their opposite ends, the lugs 49 being adapted to engage the rounded surfaces 51 and 52 of a supporting bar 53- extending transversely of the stoker and 'j0urna.led in the side members 7 and 8 of the frame 6. As shown in Figs. 1 and 4, the lugs 49 of the series of bars 47, are longer than the lugs 49 on the series of bars'48. This construction permits the upper ends of the burs of both series to lie supported at the same level with one another. The bearing lugs 50 are adapted to engage the rounded top edges flermed on plates 54 and,

55 rotutively mOlff'," on the frame 17locuted at the rear 01' the furnace and extending from one side'frame member 18 to the op msite-side frame member 19. The support bar 53 is provided on its ends with journal lugs 56 and is adapted to rock upon these lugs so that the rounded surfaces of the bearing lugs 51 and 52 which are equally spaced from the center of the journal lug 56, will have movement in opposite the fuel located on the grate will be-c0n stantly agitated and urged to move slowly down the inclined grate during its combustion, and so that the clinkers at the lower ends of the bars will be broken up. To secure this rocking movement of the support bur 53-, a crank arm. 57 is Secured to the under face thereof end connected Because ofthis construc- The purpose,'of this for \vzml and backward movement is so that with arms 60 both of which are connected with the link 31 extending from the lower end of the crank arm 42. It will thus be seen that when the link is operated in either direction, the bars of the grate 16 will be given motion in alternate directions.

The movement of the coking plates 43, 44, 45 and 46 with the links 29 and 30 is se cured in much the same manner as the movement of the bars of the grate 16, the

lates 43 and 44 being provided in this case liowever, with downwardly extending arms 58 which are connected to the link 29, the arm" of the plate43 having connection with like link 29 by means of a short link 59.

The plates 45 and 46 are similarly provided with the link 36, the arm of the plate 45 being connected with the link 30 by means of a short link 6i. ing the links :39 and 61 to connect the arms 58 and 60 of the plates 43 and 45 to the links 29 and 36, that the points at which the links and 61 are connected to the links 29 and 36, will have movement toward and away from the ends of the arms 58 and 60 when the links 29 and 30 are operated by the double arm crank 42 thus preventing the links 29 and 30 being directly connected to the arms 58 and 60.

Above the fuel pusher 28 the plate 62 is located and a plate 63 located some dis tance above the plate 62 is provided to form the bottom of'the hopper and also to provide means to. permit the fuel feeder 26 to reciprocate thereon. Between the plates 62 and 63 openings 64 are provided, these openings constituting stoke holes closed by doors 65 so that the attendant may have access to the interior of the furnace for the purpose of observing the condition of the fuel located on the coking plates and grate bars as well as for observzing the distribution of fuel on the distributing plate 27. If the fuel is found to have been improperly distributed on the distributing plate 27 the fuel feeders 26 are adjusted to distribute the coal properly, the means for adjusting the feeders consisting of a screw 66 secured to the feeders and passing through the end of the crank arm 41, the screw being provided with beads 67 at one end and having adjust-able nuts68 located on the opposite side of the crank arms 41 for the purpose of providing some lost motion between the head 67 and the nuts, so that when the nuts are adjusted, the amount of lost motion be tween the headand the nuts will regulate I the amount of movement of the feeders and consequently regulate the amount of coal to be pushed from the plate 63 on to the distributing plate 27.

The means provided for operating the dumping grates 25 consist of bars '69, 70 and 71 which extend from the front to the an of the furnace and which are con- The reason for provid-- nected with arms 72 formed on the under side of each dumping grate section, the

and the bars are supported on the transversely extending channel iron member 9, notches 74 being provided in the bars for the purpose of retaining them and the grates connected therewith in their normal position as shown in Fig. 1, when the notches are brought /to engage the channel iron member.

In the stoker operating engine which I have illustrated in Fig. 5, I have shown the engine as consisting of a steam cylinder 75 having a piston rod 76 mounted therein and connected with the arm 35 extending from the shaft 34. For the purpose of controlling the engine 'as to speed and steadiness of operation I have provided an additional cylinder 77 which is provided as is the cylinder 75 with a piston mounted on an extension of the piston rod 76, both ends of the interior of this cylinder being connected by a pipe 78 extending fromone end to the At the forward. end of the bars 69 handles 73 are provided other, the cylinder and the pipe being filled cylinder and thus act to steady the motion of the piston rod. By this means the fuel feeder 26, pusher 28, coking plates 43, 44, 45 and 46, and grate bars 47, 48, will be given a uniform and steady motion.

In operation: Coal is first placed in the hopper l3 and the engine is started so as to cause oscillation of the shafts 32, 33 and 34 through their connected links 37 and 38 and their crank arms 36, 39 and 40. With the shafts in motion the fuel feeder will be given a. forward and backward motion corresponding to the amount of movement permitted by the adjustment of the lost motion connection provided between the head 67 of the bolt 66 and the nut 68 mounted thereon. This reciprocation of the fuel feeder 26 will cause a certain amount of fuel to be taken .from the bottom of the-hopper and to be discharged from the plate 63 from which it will fall onto the distributing plate 27. When a sutlicicnt amount of fuel has accumulated on the distributing plate the fuel pusher 28 which is in constant reciprocation alternating with the reciprocation of the fuel feeder 26, will force a certain amount of fuel over the upturned edge of the distributing plate 27, from whence it will fall onto the coking plate 43. This coking plate is connected with the arm 42 of the double crank arm 42 in such a manner that it will be rocked to a substantially level position when the fuel pusher 28 is moved forwardly to discharge fuel onto the coking plate.

This permits of the fuel ,being accumulated on the coking plate 43 until it is tipped to discharge its contents onto the coking plate 45. This last mentioned coking plate being connected by the link 30 to move oppositely to the coking plate 43, will be in its substantially level position to receive the charge of fuel delivered by the coking plate 43, ready for it in turn to be tipped to dis charge its contents onto the coking plate 44. This coking plate being connected with the coking plate 43 will operate in the same manner and at the same time as the coking plate 43 so that it will be occupying its level position when the cokingplate 45 is occupying its inclined position. The coking plate 44 will therefore receive the contents of the coking plate 45 and when the coking plate 44 is tipped. the coking plate 46 which moves in the same direction and at the same time as the coking plate 45 will receive the contents of the plate 44 so that it in turn may deliver its contents onto the grate bars 47 and 48. This motion of the members 26, 28, 43, 44, 45 and 46 is being carried on con tinuously so that each time each of the plates is moved they are either receiving or discharging their contents onto other plates or bars. As the fuel is delivered to the grate bars 47, 48 it will by this time have become partially consumed and as the fuel passes over the bars 47 and 48 the (filllSlllnli t-lon thereof will be substantially completed. In order to facilitate this movement of the fuel over the grate bars 47 and -18 the alternate movement of the respective bars has been provided. This movement as above described causes one bar to move in one direction while the bars on each side of it are moving in the opposite direction, not only longitudinally but valso vertically at their ends adjacent to the frame 17. At the end of the movement of each bar the movement is reversed. This constant agitation causes the fuel to be gradually worked from the top ends of the grate bars to the lower ends thereof and during such movement the fuel is agitated and turned over a great number of times so as to produce thorough combus' tion thereof. Should any of the fuel have remained unconsumed at the end of its travel across the. grate bars, it will be discharged'onto the retarding grate 24 where the combustion will he completed. From this grate the clinkers and remaining ashes of the consumed fuel will be discharged by the fuel passing from the grate bars 47 and 48, onto the dumping grates 5 where the lastof the energy to be derived from the fuel is expended. After the accumulation of consumed fuel has been deposited on the dumping grates 25, the handles 73 of the bars (39 are lifted to remove the notches 74 from ei'igagement with the channel iron member 9 and the bars are permitted to more hackn purpos fuel.

a daptw the ills? opposite; the tiles received fr nt 1. adapted lo ope pusher. 1. 3 f

illillltil if deli el adapted the dis 1 or a pa for we t 4 plate rom not plate, and lacuna a feeder. the fuel plate-s.

3. in a mechanirz'il of a fuel -...oppcr the. stoi' r. section i the hottom of the h charge varying amounts hopper means at trilmting plate adapted to 1 r fuel delivered mit of additional gravity during its the plate. a fuel upon t ed to pi'wl tilting: u (1i liit l plates lie. plate a other, aiiziptiaz' distributing plate and from each of their preceding superimposed cooperating plates, a series of rearwardly, downwardly and longitudinally extending grate bars located beneath the coking plates and adapted to receive fuel delivered from the coking plates, said grate bars consisting of a series of bars adapted to move in first one direction and then the opposite direction, and a second set of bars adapted to move oppositely to the bars in the first set and alternately arranged therewith, said grate bars being adapted to cause the fuel to move toward their lower ends and to be discharged therefrom, a retarding grate located beneath the ends of the inclined grate bars and adapted to receive the fuel from the grate bars, and a dumping grate located beneath the retard ing grate and adapted to receive the contents of the retarding grate, and means adapted to operate the fuel feeder, the fuel pusher, the coking plates, and the grate bars.

4. In a furnace of the character described, the combination of two sets of longitudinal grate bars, the bars of one set alternating with the bars of the other, a transverse member at one end of the grate bars and having two transverse support bars one located above the other and journal pins located between the transverse support bars, one set of grate bars having lugs at one end adapted to engage one of saidsupport bars, the other set of grate bars having lugs adjacent to the lugs of the first set, adapted to engage the other support bar, means for rocking the transverse member about its journal pins and adapted to impart alternating hackward and forward movement to the grate bars, and rock plates adapted to support the opposite end of the grate bars, adapted to carry the plate supported ends of the backwardly moving grate bars at a lower level than the plate supported ends of the forwardly moving grate bars,

In combination in a mechanical Stoker, two sets of longitudinal grate bars, the bars of one set alternating with the bars of the other set, a transverse member at one end of the grate bars having two support bars, one of said support bars being located above the other, journal pins located in alinement with and midway between the transverse support bars, one set of grate bars having lugs at one end adapted to engage one of said support bars, the other set of grate bars having lugs adjacent to the lugs of the first set adapted to engage the other bar, means for rocking the transverse member about its journal pins and adapted to impart alter nating backward and forward movement to the grate bars, and rock plates adapted to support the opposite ends of the grate bars, said rock plates being adapted to carry the plate supported ends of the backwardly moving grate bars at a lower level than the plate supported ends of the forwardly moving grate bars.

In testimony whereof, I have hereunto subscribed my name this 1 day of May, 1915.

JENKIN P. DAVIS.

Witnesses:

WALTER F. MURRAY, W. Tnorm'ros Boeaar 

